> [Relocating loaders go back to the 1940s. They're older than> assemblers. I'm not sure when the first linker, as opposed to loader,> appeared, but I would be surprised if it were as late as> Fortran. -John]

Relocating is already mentioned in von Neumann's writings (1948) where
it is called "preparatory routine"; see:

-- Tomasz
[The earliest reference I know is Mauchly, "Preparation of Problems to
EDVAC-typy Machines" in 1947, which describes a relocating loader for
library routines. It's in "The Origins of Digital Computers" edited
by Brian Randall. -John]